Week 9: Asthma and COPD Flashcards
asthma
Asthma is a chronic respiratory condition associated with airway inflammation and hyper responsiveness causing reversible obstruction of the airways. Acute asthma involves:
- Bronchospasm (smooth muscle spasm narrowing airways).
- Excessive production of secretions (plugging airways).
RF for asthma
- Personal/familial history of atopy
- Inner city environment
- Obesity
- Viral infections in early childhood
- Smoking
protective factors for asthma
- Vaginal birth
- Increasing sibship
triggers for asthma
e.g. exercise, allergen, irritant exposure, change in weather and viral resp infection- cause an inflammatory cascade within the bronchial tree
presentation of asthma
- Wheeze, shortness of breath, chest tightness, cough
- Symptoms worse at night and in early morning
- Symptoms present in response to exercise, allergen exposure and cold air
- Symptoms present after taking aspirin or beta-blockers or NSAIDs(ask about new drugs)
- History of atopy e.g. eczema and hay fever
- Low FEV volume (FEV:FVC ratio <70%)
- Aggravating factors for attack
- Cold symptoms I.e. UTRI
- Cold air
- Exercise
- Cig smoke/ pollution
- Allergens
diagnosis of asthma
clinical assessment
diagnostic test
clinical assessment in the diagnosis of asthma
- History of recurrent episodes (attacks) of symptoms, ideally corroborated by variable peak flow when symptomatic and asymptomatic.
- Symptoms of wheeze, cough, breathlessness and chest tightness that vary over time.
- Recorded observation of wheeze heard by a healthcare professional.
- Personal/family history of other atopic conditions (particularly atopic eczema/dermatitis, allergic rhinitis).
- No symptoms/signs to suggest alternative diagnoses.
diagnostic tests
should be done when patient is asymptomatic vs symptoms
e. g. peak flow
e. g. spirometry
e. g. FeNO
e. g. CXR
diagnosing children under 5 with asthma
Children under five or those unable to perform objective tests- use clinical judgement based on positive objective test results and presentation to determine likelihood of asthma
DD for asthma
- Bronchiolitis à in very young children
- GORD- can cause cough on lying down
- inhalation of foreign object
- Croup (inspiratory stridor)
complications of asthma
- Pneumonia
- Pneumothorax
- Resp failure and arrest à see medicine block management
ollow up for asthma
annually and risk of asthma attack assessed
FVC
The volume breathed out during the forced expiration.
FEV1
The volume breathed out during the first second
FEV1/FVC
The proportion of the FVC that is breathed out in the first second
PEFR
The Peak Expiratory Flow Rate – the gradient of the graph at time 0, which corresponds to the highest rate of flow of air from the lungs.
spirometry
- Preferred over Peak flow- can be used for initial confirmation of asthma
- Calculates FVC and FEV1
- Can also confirm reversibility in subjects with pre-existing obstruction of airway (after use of bronchodilator)
eak flow
- Measures peak expiratory flow rate
- Simplest test
- Important role in management of established asthma
interpretation
- Patients peak flow can be compared with listed normal for their age, sex and height
- Patients record peak flow diary – can provide objective warning of clinical deterioration
peak flow technique
- Advise the patient to take in a deep breath and expel it as rapidly and as forcefully as possible into the meter.
- The very first part is all that matters for this test and it is not necessary to empty the lungs completely.
- Record the best of three tests. Continue blows if the two largest are not within 40 L/minute, as the patient is still acquiring the technique.
FeNO
- Measure amount of nitric oxide in breath
- Increased levels related to lung inflammation and asthma
- affected by smoking and inhaled corticosteroids
CXR
- Normally normal even in severe asthma
- Not used routinely in assessment of asthma
- Could be used with atypical history/exam
4 principles of asthma management
- Control symptoms
- Prevent exacerbation
- Achieve best possible lung functions
- Minimise side effects
stepwise approach to asthma
-
Step 1 (mild, intermittent asthma)
- Salbutamol (Beta 2-agonist)
- Everyone offered and should be used PRN
-
Step 2 (if use of salbutamol more than 3 times a week, symptoms more than 3 times a week, waking due to asthma more than once a week)
- Inhaled corticosteroid
-
Step 3 (if Beta-2 agonist/ inhaled steroid not enough)
- Add on:
- Leukotriene receptor antagonist (LTRA) before treatment with a long acting beta 2 agonist (LABA)
- LABA should never be used without concurrent use of inhaled steroid
-
Step 4 (persistent poor control)
- Add beclomethasone
- And/or theophylline or beta2-agonsit tablet
-
Step 5
- Continuous or frequent use of oral steroids, maintaining high dose inhaled steroids
- (Referral to resp doctor at step 4-5)
- Omalizumab- option for treating severe persistent allergic IgE mediated asthma
first step in treating asthma
get on SABA e.g. salbutamol
step 2 in asthma mangement
low dose ICS
e.g. prednisolone
step 3 in asthma management
add LTRA e.g. Montelukast or LABA e.g. salmeterol depending on guidelines
step 4 in athma management
increase ICS to medium dose e.g. beclamethasone
add LTRA
stop LABA if no response
step 5 asthma management
specialist
LABA - what to remember
always prescribe with corticosteroid
asthma management key points
- Achieve early control
- Step up or down medication to enable optimum control
- Lowest dose of inhale steroid possible
- Check compliance e.g. taking medication and inhaler technique
normal spirometry finding
a normal FEV1, FVC and FEV1/FVC ratio.
restrictive spirometry
a reduced FVC but with a normal FEV1/FVC ratio. [The FEV1 is reduced in proportion to the FVC]
e.g. pulmonary fibrosis
obstructive spirometry
a normal FVC but with a reduced FEV1 and hence FEV1/FVC ratio. In obstruction, the PEFR is also reduced
<70%
spirometry and reversibility
Bronchodilator reversibility typically involves repeating spirometry testing 20 – 30 mins after administering a dose of bronchodilator (typically Salbutamol 2 x 200mcg puffs, ideally via a large volume spacer). If there is ‘reversible’ airways obstruction, there will be an improvement in the FEV1/FVC ratio.
types of inhalers
MDI- pressurised metered dose inhalers
DPIs- dry powder inhalers
SMIs- soft mist inhalers
inhaler technique
generates an ‘aerosol’ which is inhaled.
- Test the inhaler- shake inhaler and press canister to release puff into air
- Now check that there is nothing inside the mouth piece and shake the inhaler well
- Sit or stand up straight and tilt your chin up
- Breathe out gently and slowly away from the inhaler until lungs feel empty
- Put lips around the mouthpiece to make a tight seal
- Start to breathe in slowly and steadily and at the same time press the canister on the inhaler once
- Continue to breathe in slowly until your lungs feel full
- Hold breathe for 10 seconds then breathe out gently away from your inhaler
- Repeat step 30-1 min later if required
- If inhaler contains steroids- rinse mouth with water
Different drug groups of inhaler:
- SABA = Short Acting Beta Agonist
- LABA = Long Acting Beta Agonist
- SAMA = Short Acting Antimuscarinic (rarely used in asthma)
- LAMA = Long Acting Antimuscarinic (rarely used in asthma)
- ICS = Inhaled corticosteroids
Some inhalers contain single agents; some are combinations. Common combinations are:
- ICS/LABA (can be used in asthma and COPD)
- LABA/LAMA (mainly used in COPD)
- ICS/LABA/LAMA (mainly used in COPD)
spacers
Spacers are useful devices which can improve inhaler technique. Several options are available.
features of mild asthma
no features of severe asthma
PEFR >75%
features of moderate asthma exacrbatuon
no features of severe
PEFR 50-75%
features of severe asthma exacerbation
if any on of the following
- PEFR 33-50% of best predicted
- cannot complete sentences in 1 breath
- RR >35/min
- HR >110/min
features of severe asthma exacerbation
if any one of the following
- PEFR <33%
- sat <92% of ABG pO2<9kPa
- cyanosis, poor resp effort, silent chest
- exhuastion, confusion, hypotension, arrhthmias
- normal pCO2
near fatal asthma exacerbation
- rasised pCO2
management of asthma exacerbation
Acute Asthma Management:
- ABCDE
- Aim for SpO2 94-98% with oxygen as needed, ABG if
- sats <92%
- 5mg nebulised Salbutamol (can repeat after 15 mins)
- 40mg oral Prednisolone STAT (IV Hydrocortisone if
- PO not possible)
If severe:
- Nebulised Ipratropium Bromide 500 micrograms
- Consider back-to-back Salbutamol
If life threatening or near fatal:
- Urgent ITU or anaesthetist assessment
- Urgent portable CXR
- IV Aminophylline
- Consider IV Salbutamol if nebulised route ineffective
COPD
- COPD is an umbrella term which encompasses emphysema and chronic bronchitis
- Chronic obstructive pulmonary disease (COPD) is a common, treatable (but not curable) and largely preventable lung condition.
- It is characterised by persistent respiratory symptoms (such as breathlessness, cough, and sputum) and airflow obstruction (usually progressive and not fully reversible).
Airflow obstruction results from chronic inflammation caused by exposure to noxious particles or gases (usually tobacco smoke but also from environmental and occupational exposures
COPD pathophysiology
COPD: Causes and risk factors
- Smoking
- Exposure to air pollution.
- Breathing second hand smoke.
- Working with chemicals, dust and fumes.
- Alpha-1 deficiency.
- Childhood respiratory infection.
presentation of COPD
- FEV1/FVC ratio is below <70% - non reversible with bronchodilators
- Chronic cough w or without sputum
- Shortness of breath during activity
- Wheezing
- Ankle oedema
- Cor pulmonale
diagnosis of COPD
- Spirometry
- CXR- can see bigger alveoli à air trapping à shows up as hyperdense
- Hyperinflated chest, flat diaphragm
- Severity of COPD is based on decreased FEV1
- Can use MRC dyspnoea scale (symptomatic test)
- Other tests
- Alpha 1 antitrypsin level (genetic condition causing early onset COPD, even in people with no risk factors)
- Investigations for heart disease (e.g. ECG, natriuretic peptide, echocardiogram)
- Investigations for other lung disease (e.g. CT thorax, sputum culture)
- Oxygen saturations (to check for hypoxia)
empysema
Emphysema refers to a radiological/pathological change: “a condition of the lung characterized by abnormal, permanent enlargement of airspaces distal to the terminal bronchiole, accompanied by the destruction of their walls, and without obvious fibrosis”
- Damage to walls of alveoli
- Rather than lots of small alveoli, they breakdown forming larger alveoli à unable to support bronchioles
- Bronchioles collapse and trap air inside the lungs
- Changes in emphysema are irreversible
causes of empysema
- Smoking (must stop smoking to stop it getting worse)
- Alpha 1- antitrypsin deficiency
chronic bronchitits
Chronic bronchitis is the clinical term for cough and sputum production for at least 3 months in each of 2 consecutive years.
- Chronic inflammation of the bronchioles
- Inflammatory changes like asthma
- Instead of responding to allergen, it responds to irritants like cigarette smoke
- Not T1 hypersensitivity
- Non-reversible
- Increased mucus and inflammation that causes narrowing of the airway → not bronchoconstriction
management of COPD general
- Smoking cessation advice e.g. nicotine replacement therapy
- Vaccinations e.g. annual influenzas and pneumococcal
- Pulmonary rehabilitation
- pharmacological
- inhaled treatment
- prophylactic antibiotics
- LTOT
- mucolytics
pulmonary rehab
- Increase exercise tolerance
- Anxiety management
- Breathing technique
- Teaching of how to clear chest of sputum
inhaled treatment
Make sure patient has correct inhalation technique. Nebulised treatment should be considered for patients with distressing or disabling breathlessness
- Initial treatment: SABA or SAMA
- Step up treatment for patient without asthmatic features or features suggesting steroid responsiveness: LABA and a LAMA (discontinue SAMA if LAMA given)
- SABA continued throughout all stages of treatment
- Patients on LAMA and LABA who have severe exacerbations or at least 2 moderate exacerbations, consider addition of ICS INHALER (TRIPLE THERAPY)
- Step up treatment for patient with asthmatic features or features suggesting steroid responsiveness
- LABA and ICS
- Patients on LABA and ICS who have severe exacerbations or at least 2 moderate exacerbations, consider addition of LAMA
prophylactic antibiotics
azithromycin to reduce risk of exacerbation in patients who are non-smokers, have had all other treatment option optimised and have prolonged or frequent exacerbation with sputum production or resulting in hospitalisation- ensure sputum culture and sensitivity
mucolytic treatment
carbocyteine
Long Term Oxygen Therapy → oxygen reduction
- Extended periods of hypoxia cause renal and cardiac damage – can be prevented by LTOT
- LTOT to be used at least 16 hours/day for a survival benefit
- LTOT offered if pO2 consistently below 7.3 kPa, or below 8 kPa with cor pulmonale
- Patients must be non-smokers and not retain high levels of CO2
- O2 needs should be balanced with loss of independence and reduced activity which may occur
- Note: oxygen is not a treatment for breathlessness; it is a treatment to help prevent organ hypoxia
contorlled oxyegn therapy
- Stop CO2 retention
Asthma-COPD overlap syndrome
NICE calls this “Asthmatic features/features suggesting steroid responsiveness”
This includes any previous, secure diagnosis of asthma or of atopy, a higher blood eosinophil count, substantial variation in FEV1 over time (at least 400 ml) or substantial diurnal variation in peak expiratory flow (at least 20%).
This might happen when:
- A person has ‘confirmed’ asthma (i.e. has been investigated as recommended in topic 3) but continues to smoke (or is exposed to occupational risk factors)
- A person has other atopic conditions and develops COPD.
- A person with COPD is noted to have a raised eosinophil count.
A person with COPD is noted to have a raised
eosinophil count
COPD complications
- Exacerbations of COPD
- Cor pulmonale
- Type 1 respiratory failure (‘hypoxic’ respiratory failure)
-
Type 2 respiratory failure (‘hypercapnic’ respiratory failure)
- Blue bloaters
- Secondary polycythaemia- chronic hypoxia
- Anxiety and depression
Cor pulmonale
- right sided heart failure
- due to pulmonary hypertension à hypoxia causes vasoconstriction of pulmonary BV
- pulmonary hypertension results from hypoxia, inflammation, and loss of alveolar capillaries (related to emphysematous change).
- increased pressure In the right ventricles due to pulmonary hypertension due to chronic hypoxiaà blood flow back to the RA reduced- ankle oedema
blue bloater
Bronchitis
- CO2 retention (insensitive to it
- Type 2- hypercapnic resp failure
